Tagged: monoclonal antibodies

Role of extensin arabinosylation in root defence

Extensins are hydroxyproline-rich glycoproteins thought to strengthen the plant cell wall, one of the first barriers against pathogens, through intra- and intermolecular cross-links. The glycan moiety of extensins is believed to confer the correct structural conformation to the glycoprotein, leading to self-assembly within the cell wall that helps limit microbial adherence and invasion. However, this role is not clearly established. Castilleux et al. used Arabidopsis thaliana mutants impaired in extensin arabinosylation to investigate the role of extensin arabinosylation in root–microbe interactions. Mutant and wild-type roots were stimulated to elicit an immune response with flagellin 22 and immunolabelled with a set...

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Quercus suber

AGPs and pectins during cork oak ovule development

Quercus suber is an extremely important forest species in European Western Mediterranean regions, due to its ecological value and economic potential, allowing local sustainable use of natural resources. Although it has a long and complex reproductive cycle and recalcitrant seeds, little is known about what occurs during female gametogenesis. The plant cell wall’s main components arabinogalactan proteins (AGPs) and pectins perform common functions in cell differentiation and organogenesis of reproductive structures, acting as signalling molecules, in sporophyte–gametophyte transition and in pollen–pistil interactions. Lopes et al. assessed the distribution of these molecules during cork oak ovule development.

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AGPs in Trithuria reproductive structures

AGPs in Trithuria reproductive structures

Trithuria is the sole genus of Hydatellaceae, a family of the early-divergent angiosperm lineage Nymphaeales. In order to help determine the early evolution of angiosperm cell-wall structures, Costa et al. use immunocytochemical techniques to examine arabinogalactan protein (AGP) epitopes in T. submersa and find intense labelling in the anthers and in the intine wall, the latter associated with pollen tube emergence. The results agree with labellings obtained for Arabidopsis and confirms the importance of AGPs in angiosperm reproductive structures as essential structural components and probably important signalling molecules.

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The green alga Penium under white light (top) and labelled with monoclonal antibody

Algal cell walls and their diversity: a PhD position

Zoë Popper, an Annals of Botany Editor, has a funded  PhD position to characterise algal cell walls and make cell wall-directed monoclonal antibodies, using biochemical analysis and immunocytochemistry. The project will also generate and investigate cell wall mutants of the putative model charophycean green alga, Penium margaritaceum. As Zoe and co-authors* wrote in their review earlier this year, Penium margaritceum (a charophycean green alga) is rapidly emerging as a model organism, and several characteristics make it a particularly appropriate tool for investigating all cell-wall biochemistry. It is a unicellular organism in the CGA, and it produces only a primary cell wall. Additionally, it has a...

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